Twins Phoebe and Max are enjoying their superhero lifestyle, but when one 'save' goes awry, the Thundermans are sent back to Hiddenville. While Hank and Barb enjoy their return, and Billy and Nora look forward to a normal high school life, Max and Phoebe are determined to regain their superhero status.

Bob Parr has given up his superhero days to log in time as an insurance adjuster and raise his three children with his formerly heroic wife in suburbia. But when he receives a mysterious assignment, it's time to get back into costume.

When a young boy finds a message from his late grandfather, his ordinary family discovers an extraordinary secret about themselves — and the universe.

Taking place after the final episode, the Iggarashi Family and FENIX reunite for one last battle against Giff and the Deadmans.